Bringing back memories of what it was like to watch a high-school student giving an oral report he forgot to prepare for, the unwatchable documentary “Brother, Can You Spare a Dollar?” is a shoddy, slapdash look at issues raised by the Great Depression that neither gives an adequate overview nor manages to argue a coherent thesis.

Veering madly from one subject to another, director Thom Hoffman mixes footage of interviews with seemingly randomly selected Depression survivors, and a grab-bag of newsreel clips and sound bites. One moment we’re on the writing of the song “Brother, Can You Spare a Dime?,” the next we’re learning how business was at Coney Island (surprisingly strong), then we’re on to stickball, radio and “that funny little box . . . called television.”

Hoffman next jumps to a discussion of the regulations and agencies at issue in the 2008 recession, but again with a depth of research and organizational technique that suggests a stack of notecards flung in the air and read off in the order they were picked up. The vaguest and most hackneyed questions are posed but not answered: Can we rise above our divisions? Can we meet the challenges of globalization? How will this generation turn out? Great minds have grappled with these ideas. For a look at how not-so-great ones do so, check out this film.